1. Field of the Disclosure
This invention relates to a Vacuum Cleaner particularly, to a cylinder-type vacuum cleaner which is designed for stable, safe and easy use on both a flight of stairs and also on a flat surface such as a floor.
2. Description of the Related Art
There are very few prior art machines which have been designed for use on stairs. Those that have, embody awkward and cumbersome mechanisms which protrude to engage with the stairs or body parts which engage with the stair step and depend on the body of the vacuum cleaner being precisely positioned at a particular angle so as to allow the body of the vacuum cleaner to engage with the stairs in order to prevent the Vacuum Cleaner from slipping back down the stair case.
None of these prior art vacuum cleaners are designed or intended to be moved up or down a flight of stairs other than by the user lifting the entire vacuum cleaner and repositioning it on another part of the flight of stairs. This results in a cumbersome manoeuvre. It would be far more convenient if the vacuum cleaner could be pulled up the flight of stairs in a smooth continuous movement by dragging or sliding the body of the vacuum cleaner. The configuration of prior art vacuum cleaners is such that dragging or sliding the machine is difficult and awkward. No Prior art machines are designed in such a way so as to span across two or more stair-treads in order to provide increased stability and also facilitate smooth ascent of the stair case.
Further to this, no prior art machines which are intended to overcome the problems associated with use on a stair case, are configured so that the centre of gravity of the machine creates its' own inherent stability or have a curved undercarriage which is specifically designed to aid movement of the vacuum cleaner up a flight of stairs and yet still allow conventional use of the machine on a flat surface such as a floor. Nor do any prior art machines implement rotating ground engaging members that can be engaged or disengaged to allow movement in one direction only, in order to act as a break against slipping downstairs. No prior art machines which are intended to overcome the problems associated with use on a stair case, are configured so that rotating members incorporated into the front of the vacuum cleaner will allow the nose to ascend a step with very little resistance or have any combination of any of these features which would make them suited for us on a stair case, while retaining the ability to be used on a flat floor.
With Reference to Prior art Machines:
U.S. Pat. No. 5,755,007 refers to a portable cleaning apparatus which attempts to solve some of these issues but does not address the issue of the inability of a machine to smoothly ascend up a stair case by the use of a curved undercarriage. It does not have lockable ground engaging members but rather, relies upon the body of the machine contacting the stair tread in order that friction between the step and the machine body part will act as a break or grip.
U.S. Pat. No. 5,937,477 refers to a portable cleaning apparatus which attempts to solve some of these issues but does not address the issue of the inability of a machine to smoothly ascend up a stair case by the use of a curved undercarriage. It does not have lockable ground engaging members but rather, relies upon the body of the machine contacting the stair tread in order that friction between the step and the machine body part will act as a break or grip. It also does not have the motor of the machine located in such a place that the centre of gravity of the machine aids stability.
U.S. Pat. No. 2003/0121120 A1 refers to a vacuum cleaner which attempts to solve some of these issues but does not address the issue of the inability of a machine to smoothly ascend up a stair case by the use of a curved undercarriage. It does not have lockable ground engaging members but rather, relies upon the body of the machine contacting the stair tread when placed at a particular angle, in order to act as a break or grip.